Mucoproteína versus alfa-1-glicoproteína ácida: o que quantificar?

Jornal Brasileiro de Patologia e Medicina Laboratorial 01/2002; 38(2). DOI: 10.1590/S1676-24442002000200004
Source: DOAJ


A quantificação sérica da alfa-1-glicoproteína (GPA) ácida é útil no diagnóstico e no acompanhamento dos processos agudos resultantes de múltiplas causas. Esta proteína também pode ser estimada pela quantificação da mucoproteína (Muco), ensaio que reflete as glicoproteínas com elevado teor de açúcar, entre as quais a GPA é majoritária. O objetivo deste trabalho é verificar a correlação e a performance analítica das determinações de mucoproteína (Muco) e alfa-1-glicoproteína ácida (GPA), propondo uma equação de regressão linear. Amostras de soros de 540 pacientes, com idades entre 10 e 79 anos (média de 34,6), predominando mulheres (71,3%), foram analisadas simultaneamente para Muco (Winzler, manual com reagentes próprios) e GPA (imunoturbidimetria automatizada, Roche; Cobas mira). A análise de regressão, fixando a Muco como variável dependente, apresentou Muco (mg/dl em tirosina) = 0,031 x GPA (mg/dl) + 0,8 (r = 0,91); e, fixando o intercepto em zero, Muco = 0,039 x GPA (r = 0,98). A imprecisão interensaio foi de 23,4% e 5,2% (coeficiente de variação), respectivamente, para Muco e GPA. Conclusão: a elevada variabilidade analítica da quantificação da mucoproteína pelo método de Winzler recomenda que este ensaio seja substituído pela dosagem da alfa-1-glicoproteína ácida. Quando necessário, recomendamos estimar a mucoproteína, quantificando a alfa-1-glicoproteína ácida com ensaios de mesmo desempenho que o do utilizado neste trabalho, e usar a equação de regressão AGP (mg/dl) x 0,039 = Muco (mg/dl em tirosina).


Available from: Cyntia Fadel-Picheth, Dec 17, 2013
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